1. Field of the Invention
The present invention relates to surgical instruments and, particularly, to an instrument for biopsy sampling of tissue. Still more particularly, the present invention relates to an endoscopic biopsy instrument that obtains core biopsy samples and integrates two or more biopsy-sampling modalities.
2. Background of Related Art
Biopsy is the removal and study of body tissue for medical diagnosis. Typically, physicians obtain biopsy samples in order to detect abnormalities such as cancer and determine the extent to which cancerous tissue has spread. They use various biopsy instruments to acquire tissue samples from different areas of the body. Many current biopsy instruments, however, cannot retrieve full core samples of tissue, do not provide versatility in sampling methods, or are overly intricate in design and manufacture.
During a biopsy tissue-sample procedure performed on a body lumen, a physician generally uses an endoscope to provide a passageway for entry of the biopsy instrument into the body. Having thus secured access to the biopsy site, the physician uses some device to extract a tissue sample from the wall of the target body lumen. Usually, the walls of body lumen, such as the esophagus, the gastrointestinal tract, or the urinary tract, have three layers: the surface mucosal or epithelial layer comprised of mucus; the submucosal layer, which is below the mucosal layer; and the muscle layer. Many current biopsy devices can only take tissue from the surface mucosal layer and also cannot retrieve full core samples.
In many situations, physicians may desire full core samples because, with larger cross-sections of tissue types, they can more accurately determine the extent to which cancer has spread. It is also desirable to obtain full, clean core samples that have not been crushed by devices penetrating into tissue. Moreover, it may be desirable to obtain a full core sample without having to penetrate past a desired depth of tissue in order to obtain a corresponding desired depth of core sample. It would be preferable to insert a biopsy needle only as far as necessary to obtain a full core sample to minimize trauma to the patient.
Further, many current devices lack versatility. Many devices today extract tissue samples through aspiration, brush cytology, or pinch biopsy. In the case of aspiration, a physician inserts a very fine needle into the wall of the target tissue and draws fluid, typically saline, through the needle. The physician thus collects some surface tissue cells. In the case of brush cytology, a physician introduces a brush through the lumen of the endoscope to collect tissue cells by scraping the surface of the target site. In the case of pinch biopsy, a physician inserts a bioptome, having a pair of opposed jaw cups, through the lumen of the endoscope, to the tissue site. The physician may then close the jaws around the target surface and pinch away a sample from the surrounding tissue.
Typically, current devices may employ only one of these methods to obtain tissue samples. Thus, a physician who desires tissue samples obtained through both aspiration and brush cytology, for example, must insert one instrument, take a sample, retrieve the instrument, insert a second instrument, take a second sample, and then retrieve the second instrument. Such practice is time consuming and leads to procedural inefficiency.
Many current instruments also have an overly complex design. Devices that might otherwise fulfill one of the aforementioned needs, such as the need to capture core samples, for example, often employ complex cutting mechanisms held in sheaths or housings requiring very exact tolerances.
In light of the foregoing, there exists a need for a biopsy tissue-sampling device that effectively obtains a full core tissue sample, accommodates multiple sampling modes, and is simple in design and inexpensive to manufacture.
It is therefore an object of the invention to provide a surgical instrument that is able to obtain a full core biopsy tissue sample with minimal trauma to the patient.
It is a further an object of the invention to provide a surgical instrument that integrates two or more biopsy tissue sampling modalities.
It is another object of the invention to provide a surgical instrument that integrates three biopsy tissue sampling modalities.
Additional objects and advantages of the invention will be set forth in the description which follows and, in part, will be obvious from the description or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention comprises an instrument for collecting body tissue, comprising: a needle having an axial center, an exterior surface, a hollow interior, a distal end and a proximal end, wherein the distal end is capable of penetrating body tissue; a flexible cutting extension coaxially and slidably disposed around the exterior surface of the needle, the cutting extension including a blade surface having a cutting edge wherein the blade surface is biased toward the axial center of the needle such that the cutting extension moves toward the axial center of the needle when urged past the distal end of the needle and the edge cuts tissue located at the distal end of the needle and the blade surface covers the distal end of the needle so that tissue that has entered the hollow interior of the needle is trapped in the hollow interior of the needle.
In a preferred embodiment, the cutting extension comprises a symmetrical arrangement of blade surfaces biased toward the axial center of the needle.
In another preferred embodiment, the cutting extension includes a plurality of blade surfaces biased toward the axial center of the needle.
In another-preferred embodiment, the blade surface of the flexible cutting extension forms an opening and at least part of the surface forming the opening forms the cutting edge.
In another preferred embodiment, the instrument further comprises: a first tubular member having a proximal end and a distal end connected to the proximal end of the needle; a second tubular member coaxially disposed around the first tubular member, the second tubular member having a proximal end and a distal end connected to the proximal end of the cutting extension; and a handle mechanism connected to the proximal ends of the first and second tubular members, the handle mechanism having a housing and a means for extending the cutting extension beyond the distal end of the needle.
In another preferred embodiment, the means for extending the cutting extension comprises a resilient member connected between the handle housing and the second tubular member for extending the cutting extension connected to the second tubular member distally beyond the distal end of the needle.
In still another preferred embodiment, the means for extending the cutting extension comprises a first hub connected to the first tubular member and a second hub connected to the second tubular member, the second hub slidable relative to the first hub to extend the cutting extension relative to the needle.
In another preferred embodiment, the instrument further comprises a third tubular member coaxially disposed around the first and second tubular members and having a proximal end connected to the handle housing.
In yet another preferred embodiment, the instrument further comprises a fourth tubular member disposed within the third tubular member a brush coaxially disposed in the fourth tubular member.
In another preferred embodiment, the instrument further comprises a brush coaxially disposed in the first tubular member.
In another preferred embodiment, the proximal end of the first tubular member is connected to a vacuum source for cell aspiration.
In another preferred embodiment, an instrument for collecting body tissue is provided, comprising: a tubular cutting member having an exterior surface, a proximal end and a distal end capable of penetrating body tissue; a flexible cutting extension coaxially and slidably disposed around the exterior surface of the cutting member, the flexible cutting extension having a proximal end and a distal end capable of cutting tissue located at the distal end of the cutting member and covering the distal end of the cutting member so that tissue that has entered the needle is retained in the cutting member; a first tubular member connected to the cutting member; a second tubular connected to the cutting extension; a handle mechanism connected to the first and second tubular members such that the flexible cutting extension may be extended beyond the distal end of the cutting member.
In another preferred embodiment, an instrument for collecting body tissue is provided, comprising: a needle having an axial center, an exterior surface, a hollow interior, a proximal end and a distal end capable of penetrating body tissue; a flexible cutting extension coaxially and slidably disposed around the exterior surface of the needle, the flexible cutting extension including at least a blade surface having a cutting edge and being biased toward the axial center of the needle such that the flexible cutting extension moves toward the axial center of the needle when urged past the distal end of the needle and the edge cuts tissue located at the distal end of the needle and the blade surface covers the distal end of the needle; a first tubular member having a proximal end and a distal end connected to the proximal end of the needle; a second tubular member coaxially disposed around the first tubular member, the second tubular member having a proximal end and a distal end connected to the proximal end of the cutting extension and being moveable relative to the first tubular member to provide relative movement between the needle and the flexible cutting extension.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention as claimed.